Trifluoroacetic acid → HCID 58221390, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred ice cooled solution of tetrahydro-2H-thiopyran-4-carbaldehyde (2.1 g, 16.1 mmol) in DCM (30 mL) was added 3-bromophenylhydrazine hydrochloride (1.0 eq., 3.6 g) in one portion. The resulting mixture was stirred at 0° C. for 10 min before TFA (3.0 eq., 5.52 g) was added dropwise via syringe. The resulting mixture was stirred at 0° C. for 10 min and then at rt for 4 h. After this time the mixture was poured into ice and NH3H2O (28%) and extracted with EtOAc. The combined organic extracts were washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was dissolved in benzene and evaporated in vacuo to give 6-bromo-2′,3′,5′,6′-tetrahydrospiro[indole-3,4′-thiopyran] and 4-bromo-2′,3′,5′,6′-tetrahydrospiro[indole-3,4′-thiopyran] in a ratio of 1 to 1.3. Mass Spectrum (ESI) m/e=282.0 [(M+1) (79Br)] and 284.0 [(M+1) (81Br)].

Provenance & Evidence